BRIJS Jeroen Dr.
University of Innsbruck
Department of Zoology
Research Group: Applied Animal Ecology
Raum 01/217
Telefon: +43 512 507-51886
E-Mail: Jeroen.Brijs@uibk.ac.at
My research philosophy
Specific research project
As the global demand for fish rises and aquaculture expands rapidly, ensuring the welfare of fish during slaughter becomes increasingly imperative, given their susceptibility to pain and distress. Achieving humane slaughter entails either instant killing or rendering fish unconscious until their demise. However, distinguishing between dead, unconscious, or immobilized states during the slaughter process poses significant challenges. To address this issue, Dr. Jeroen Brijs and Prof. Thorsten Schwerte at the University of Innsbruck and Dr. Albin Gräns at the Swedish University of Agricultural Sciences are collaborating on an international effort. They aim to develop a portable, user-friendly method capable of real-time assessment of various stunning and slaughter techniques at aquaculture facilities. This innovative approach involves monitoring brain activity to determine if stunning or slaughter methods instantly renders fish dead or irreversibly unconscious. By providing insights into enhancing stunning and slaughter practices, this project endeavors to alleviate the suffering of countless individual fish.
Curriculum Vitae
2023-present Postdoctoral Researcher, University of Innsbruck, Austria
Research focus: Safeguarding the welfare of fish worldwide
2020-2023 Postdoctoral Researcher, University of Hawai‘i at Mānoa, USA
Research focus: Effects of heatwaves on Hawaiian coral reef fishes
2018-2020 Postdoctoral Researcher, Swedish University of Agricultural Sciences, Sweden
Research focus: Improving fish welfare in commercial fish production systems
2017-2018 Postdoctoral Researcher, University of Gothenburg, Sweden
Research focus: Cardio-respiratory responses of fish to environmental stressors
2012-2017 Doctoral Student (PhD), University of Gothenburg, Sweden
Research focus: Gastrointestinal motility and blood flow in teleosts
2007-2010 Advanced Research Technician, University of Waikato, New Zealand
Research focus: Evaluating the impacts of invasive fish on native flora and fauna
2005-2007 Masters Student (MSc), University of Waikato, New Zealand
Research focus: Ecophysiology of adaptive oxygen transport in NZ mudfishes
2002-2005 Bachelor Student (BSc), University of Waikato, New Zealand
My publications
Brijs, J. et al. (in review). Mind the gap: the need for scientifically validated humane slaughter practices in Mediterranean seabream and seabass aquaculture. Aquaculture (Q1, IF = 3.9).
Roome, T. C., et al. (in review). Limited climate tradeoffs in corallivore palatability and wound recovery among Hawaiian reef-building corals. Coral Reefs (Q1, IF = 2.9).
Gräns, A., et al. (2025). Stunning challenges: Operational indicators of insensibility flag failures in seabass and seabream, but success is not guaranteed. Aquaculture Reports (Q1, IF = 3.9).
Gräns, A., et al. (2025). From tradition to innovation: Effects of manual and automated ikejime on welfare and product quality of rainbow trout and hybrid striped bass. Aquaculture (Q1, IF = 2.7).
Brijs, J., et al. (2025). Outlasting the heat: precipitous decline of herbivorous fish fitness during marine heatwaves. Glob. Chang. Biol. 31: e70438 (Q1, IF = 12.0).
Ekstrom, A., et al. (2025). Decoding thermal resilience in fish - Acute warming tolerance is associated with neural failure in rainbow trout. Biol. Lett. 21: 20250132 (Q1/Q2, IF = 2.8).
Brijs, J., et al. (2025). Eat more, often: The capacity of piscivores to meet increased energy demands in warming oceans. Sci. Total. Environ. 973: 179105 (Q1, IF = 8.0).
Souza, T., et al. (2025). Herbivore functions in the hot-seat: Resilience of Acanthurus triostegus to marine heatwaves. PloS one 20: e0318410 (Q2, IF = 2.6).
Brijs, J., et al. (2025). Effects of electrical and percussive stunning on neural, ventilatory and cardiac responses of rainbow trout. Aquaculture 594: 741387 (Q1, IF = 3.9, n = 2).
Sundell, E., et al. (2024). The quest for a humane protocol for stunning and killing Nile tilapia (Oreochromis niloticus). Aquaculture 593: 741387 (Q1, IF = 3.9, n = 5).
Green, L., et al. (2022). Invader at the edge – Genomic origins and physiological differences of round gobies across a steep urban salinity gradient. Evol. Appl. 16: 1-17 (Q1/Q2, IF = 3.2, n = 11).
Hjelmstedt, P., et al. (2022). Assessing the effectiveness of percussive and electrical stunning in rainbow trout: Does an epileptic-like seizure imply brain failure. Aquaculture 552: 738012 (Q1, IF = 3.9, n = 18).
Brijs, J., et al. (2021). Humane slaughter of African sharptooth catfish (Clarias gariepinus): effects of various stunning methods on brain function. Aquaculture 531: 1-11 (Q1, IF = 3.9, n = 27).
Hjelmstedt, P., & Brijs, J., et al. (2021). Continuous physiological welfare evaluation of European whitefish (Coregonus lavaretus) during common aquaculture practices leading up to slaughter. Aquaculture 534: 1-10 (Q1, IF = 3.9, n = 12).
Sundell, E., et al. (2021). Energetic savings and cardiovascular dynamics of a marine euryhaline fish (Myoxocephalus scorpius) in reduced salinity. J. Comp. Physiol. B 191: 301-311 (Q2, IF = 1.7, n = 11).
Brijs, J., et al. (2020). Response to ‘The spleen as an unlikely source of red blood cells during increased activity in fishes. J. Exp. Biol. 223: 1-4 (Q1, IF = 2.6, n = 1).
Brijs, J., et al. (2020). Prevalence and severity of cardiac abnormalities and arteriosclerosis in farmed rainbow trout (Oncorhynchus mykiss). Aquaculture 526: 1-11 (Q1, IF = 3.9, n = 43).
Hjelmstedt, P., et al. (2020). Effects of prophylactic antibiotic-treatment on post-surgical recovery following intraperitoneal bio-logger implantation in rainbow trout. Sci. Rep. 10: 1-9 (Q1, IF = 3.9, n = 17).
Brijs, J., et al. (2019). Extreme blood boosting capacity of an Antarctic fish represents an adaptation to life in a sub-zero environment. J. Exp. Biol. 223: 1-11 (Q1, IF = 2.6, n = 17).
Brijs, J., et al. (2019). Remote physiological monitoring provides unique insights on the cardiovascular performance and stress responses of freely swimming rainbow trout in aquaculture. Sci. Rep. 9: 1-12 (Q1, IF = 3.9, n = 49).
Brijs, J., et al. (2019). Prospects and pitfalls of using heart rate bio-loggers to assess the welfare of rainbow trout (Oncorhynchus mykiss). Aquaculture 509: 188-197 (Q1, IF = 3.9, n = 61).
Závorka, L., et al. (2019). Laboratory captivity can affect scores of metabolic rates and activity in wild brown trout. J. Zool. 307: 249-255 (Q2, IF = 1.6, n = 6).
Brijs, J., et al. (2018). The final countdown: Continuous physiological welfare evaluation of farmed fish during common aquaculture practices before and during harvest. Aquaculture 495: 903-911 (Q1, IF = 3.9, n = 105).
Brijs, J., et al. (2018). In vivo aerobic metabolism of the rainbow trout gut and the effects of an acute temperature increase and stress event. J. Exp. Biol. 221: 1-6 (Q1, IF = 2.6, n = 23).
Ekström, A., et al. (2018). Importance of the coronary circulation for cardiac and metabolic performance in rainbow trout (Oncorhynchus mykiss). Biol. Lett. 14: 1-4 (Q1/Q2, IF = 2.8, n = 36).
Jutfelt, F., et al. (2018). Oxygen- and capacity-limited thermal tolerance: blurring ecology and physiology. J. Exp. Biol. 221: jeb169615 (Q1, IF = 2.6, n = 280).
Sundell, E., et al. (2018). Seawater acclimation affects cardiac output and adrenergic control of blood pressure in rainbow trout (Oncorhynchus mykiss) – implications for salinity variations now and in the future. Conserv. Physiol. 6: 1-11 (Q1, IF = 2.5, n = 10).
Sundh, H., et al. (2018). Effects of coeliacomesenteric blood flow reduction on intestinal barrier function in rainbow trout (Oncorhynchus mykiss). J. Fish. Biol. 93: 519-527 (Q2, IF = 1.7, n = 12).
Brijs, J., et al. (2017). Exposure to seawater increases intestinal motility in euryhaline rainbow trout. J. Exp. Biol. 220: 2397-2408 (Q1, IF = 2.6, n = 18).
Brijs, J., et al. (2017). The presence and role of interstitial cells of Cajal in the proximal intestine of shorthorn sculpin. J. Exp. Biol. 220: 347-357 (Q1, IF = 2.6, n = 18).
Brijs, J., et al. (2017). Cardiac remodelling and increased central venous pressure underlie elevated stroke volume and cardiac output of seawater-acclimated rainbow trout. Am. J. Physiol. Regul. Integr. Comp. Physiol. 312: R31-R39 (Q2, IF = 2.2, n = 37).
Brijs, J., et al. (2017). Increased mitochondrial coupling and anaerobic capacity minimizes aerobic costs of trout in the sea. Sci. Rep. 7: 45778 (Q1, IF = 3.9, n = 30).
Ekström, A., et al. (2017). Influence of the coronary circulation on thermal tolerance and cardiac performance in rainbow trout. Am. J. Physiol. Regul. Integr. Comp. Physiol 312: R549-R558 (Q2, IF = 2.2, n = 46).
Ekström, A., et al. (2017). Thermal sensitivity and phenotypic plasticity of cardiac mitochondrial metabolism in European perch. J. Exp. Biol. 220: 386-396 (Q1, IF = 2.6, n = 87).
Fillipsson, K., et al. (2017). Encystment of parasitic freshwater pearl mussel larvae coincides with increased metabolic rate and haematocrit in juvenile brown trout. Parasitol. Res. 116: 1353-1360 (Q2, IF = 2.0, n = 46).
Závorka, L., et al. (2017). Co-existence with non-native brook trout breaks down the integration of phenotypic traits in brown trout parr. Func. Ecol. 31: 1582-1591 (Q1, IF = 5.1, n = 51).
Brijs, J., et al. (2016). Cardiorespiratory up-regulation during seawater acclimation in rainbow trout: Effects on gastrointestinal perfusion and post-prandial responses. Am. J. Physiol. Regul. Integr. Comp. Physiol. 310: R858-R865 (Q2, IF = 2.2, n = 25).
Ekström, A., et al. (2016). Cardiac oxygen limitation during an acute thermal challenge in the European perch: effects of chronic environmental warming and experimental hyperoxia. Am. J. Physiol. Regul. Integr. Comp. Physiol. 311: R440-R449 (Q2, IF = 2.2, n = 93).
Sandblom, E., et al. (2016). Physiological constraints to climate warming in fish follow principles of plastic floors and concrete ceilings. Nat. Commun. 7: 1-8 (Q1, IF = 15.7, n = 165).
Sandblom, E., et al. (2016). Cardiac reflexes in a warming world: thermal plasticity of barostatic control and autonomic tones in a temperate fish. J. Exp. Biol. 7: 1-8 (Q1, IF = 2.6, n = 300).
Brijs, J., et al. (2015). Increased gastrointestinal blood flow: An essential circulatory modification for euryhaline rainbow trout migrating to sea. Sci. Rep. 5: 10430 (Q1, IF = 3.9, n = 33).
Brijs, J., et al. (2015). Experimental manipulations of tissue oxygen supply do not affect warming tolerance of European perch. J. Exp. Biol. 218. (Q1, IF = 2.6, n = 101).
Brijs, J., et al. (2014). Effects of feeding on in vivo motility patterns in the proximal intestine of shorthorn sculpin. J. Exp. Biol. 217: 3015-3027. (Q1, IF = 2.6, n = 16).
Olsson, C., et al. (2025). Beyond Ecology: The importance of gut motility in predicting species responses to climate change. J. Exp. Biol. 228: 1-11 (Q1, IF = 2.6, n = 0).
Brijs, J., et al. (2022). Animal Welfare: Using bio-sensing devices to assess farm animal welfare. Front. Physiol.: 145 (Q1, IF = 3.4, n = 3).
Brijs, J., et al. (2021). Bio-sensing technologies in aquaculture: how remote monitoring can bring us closer to our farm animals. Phil. Trans. R. Soc. B 376: 1-10 (Q1, IF = 4.7, n = 47).
Fahlmann, A., et al. (2021). The new era of physio-logging and their grand challenges. Front. Physiol. 12: 1-6 (Q1, IF = 3.7, n = 19).
Joyce, W. & Brijs., J. (2024). Integrated responses of the circulatory system to digestion. In Encyclopedia of fish physiology: From genome to environment (eds. Gillis, T. & Alderman, S.). Academic press, Netherlands (n = n/a).
Joyce, W. & Brijs., J. (2024). The gastrointestinal circulation. In Encyclopedia of fish physiology: From genome to environment (eds. Gillis, T. & Alderman, S.). Academic press, Netherlands (n = n/a).
Hicks, B., et al. (2015). Biomass estimation of invasive fish. In New Zealand Invasive Fish Management Handbook (eds. Collier, K. J. and Grainger, N. P. J.). Lake Ecosystem Restoration New Zealand and Department of Conservation, Hamilton, New Zealand. 212 p (n = 18).
Brijs., J., et al. (2025). Documentation of fish welfare following in-water electrical stunning of Atlantic salmon and rainbow trout. Prepared for Norwegian Seafood Research Fund (FHF), Norway.
Saraiva., et al. (2025). Fish stunning and killing and fish welfare during stunning and killing. Prepared for the European Food Safety Authority (EFSA), Europe.
Saraiva., et al. (2024). Research design to detect loss of consciousness and/or sensibility of fish at slaughter. Prepared for the European Reference Center for Animal Welfare for Aquatic Animals (EURCAW Aqua), Europe.
Brijs, J., et al. (2024). Fish welfare during slaughter: Weak relationship between operational and neurophysiological indicators in both seabream and seabass. Prepared for the Center for Responsible Seafood, USA.
Brijs, J., et al. (2024). Seabream and seabass welfare in aquaculture: A review of slaughter practices and future directions for humane standards. Prepared for the Center for Responsible Seafood, USA.
Brijs, J., et al. (2020). Humane slaughter of African sharptooth catfish: Effects of current and alternative stunning methods on brain function. Prepared for the Swedish Board of Agriculture, Sweden.
Brijs, J., et al. (2019). Cardiovascular disease in rainbow trout: Prevalence, severity and consequences of the disease in Nordic aquaculture. Prepared for the Swedish Board of Agriculture, Sweden.
Brijs, J., et al. (2010). Boat electrofishing survey of common smelt and common bully in the Ohau Channel in December 2009. Prepared for Environment Bay of Plenty, New Zealand.
Brijs, J., et al. (2009). Spatial and temporal abundance of mysid shrimp (Tenagomysis chiltoni) in shallow lakes in the Waikato region. Prepared for Environment Waikato, New Zealand.
Brijs, J., et al. (2009). Pest fish survey of Hokowhitu (Centennial) Lagoon, Palmerston North. Prepared for Department of Conservation, New Zealand.
Brijs, J., et al. (2009). Boat electrofishing survey of common smelt and common bullies in the Ohau Channel in December 2008. Prepared for Environment Bay of Plenty, New Zealand.
Hicks, B., & Brijs., J. (2009). Boat electrofishing survey of Lake Ngaroto. Prepared for Waipa District Council, New Zealand.
Hicks et al. (2009). Boat electrofishing survey of the upper Turitea Reservoir, Palmerston North. Prepared for Department of Conservation, New Zealand.
Hicks et al. (2009). Boat electrofishing survey of Lake Rotokaeo, Hamilton. Prepared for Department of Conservation, New Zealand
Ling, N., & Brijs, J. (2009). Utuhina Stream monitoring 2009: fish and aquatic invertebrates. Prepared for Environment Bay of Plenty, New Zealand.
Brijs, J., et al. (2008). Electrofishing survey of the fish community in the Whangamarino Wetland. Prepared for Department of Conservation, New Zealand.
Brijs, J., et al. (2008). Boat electrofishing survey of common smelt and common bullies in the Ohau Channel. Prepared for Department of Conservation, New Zealand.
Hicks et al. (2008). The use of boat electrofishing for koi carp (Cyprinus carpio) removal in the Kauri Point catchment. Prepared for Department of Conservation, New Zealand.
Hicks et al. (2007). Boat electrofishing survey of five Waitakere City ponds. Prepared for Boffa Miskell Ltd., New Zealand.
Landman et al. (2006). Lake Okareka and Tikitapu Fish Health Monitoring 2007. Prepared for Environment Bay of Plenty, New Zealand.